A 3rd generation partnership project (3GPP) long term evolution (LTE) that improves a universal mobile telecommunications system (UMTS) has been introduced to a 3GPP release 8.
The 3GPP LTE uses an orthogonal frequency division multiple access (OFDMA) in a downlink and a single carrier-frequency division multiple access (SC-FDMA) in an uplink. The OFDM needs to know in order to understand the OFDMA. The OFDM may be used since an inter-symbol interference effect can be reduced due to low complexity. The OFDM converts data to be input in serial into N parallel data and transmits it by carrying N orthogonal sub-carriers. The sub-carriers maintains orthogonally in a frequency dimension. Meanwhile, the OFDMA means a multiple access method to realize multiple accesses by providing a part of the available sub-carrier to each user independently, in a system using the OFDM in a modulation scheme.
FIG. 1 is view of an evolved mobile communication network;
As known in FIG. 1, a wireless communication system includes at least one base station (BS) 20. Each base station 20 provides communication services for specific geographical areas (generally referred to as cells) 20a, 20b and 20c. 
In this case, communications from a base station to a terminal is called as a downlink (DL) and communication from the terminal to the base station is called as an uplink (UL).
If base stations by several service providers are present in each geographical area 20a, 20b, 20c, they may occurs interference with each other.
To eliminate this interference, each service provider can provide services with different frequency bands.
However, if the frequency bands of each service provider are adjacent to each other, the interference problem still exists. This interference problem can be solved by increasing substantial frequency intervals between adjacent bands such that transmission power may be reduced or the amount of transmission resource block (RB) may be limited. However, if the transmission power may be reduced simply, since service coverage is also reduced accordingly, a measure to reduce the transmission power at an appropriate level is required without causing the interference problem.